[Federal Register Volume 83, Number 53 (Monday, March 19, 2018)]
[Proposed Rules]
[Pages 11946-11952]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-05398]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R08-OAR-2017-0672; FRL-9975-47--Region 8]


Approval and Promulgation of Implementation Plans; South Dakota; 
Regional Haze 5-Year Progress Report State Implementation Plan

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing to 
approve South Dakota's regional haze progress report, submitted as a 
revision to its State Implementation Plan (SIP) by the South Dakota 
Department of Environment and Natural Resources (DENR). South Dakota's 
SIP revision addresses requirements of the Clean Air Act (CAA) and the 
EPA's rules that require states to submit periodic reports describing 
progress toward reasonable progress goals established for regional haze 
and a determination of the adequacy of the state's existing regional 
haze SIP. South Dakota's progress report explains that South Dakota has 
implemented the measures in the regional haze SIP due to be in place by 
the date of the progress report and that visibility in mandatory 
federal Class I areas affected by emissions from South Dakota sources 
is improving. The EPA is proposing approval of South Dakota's 
determination that the State's regional haze SIP is adequate to meet 
Reasonable Progress Goals (RPGs) for the first implementation period 
covering through 2018 and requires no substantive revision at this 
time.

DATES: Comments must be received on or before April 18, 2018.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R08-
OAR-2017-0672 at http://www.regulations.gov. Follow the online 
instructions for submitting comments. Once submitted, comments cannot 
be edited or removed from www.regulations.gov. The EPA may publish any 
comment received to its public docket. Do not submit electronically any 
information you consider to be Confidential Business Information (CBI) 
or other information whose disclosure is restricted by statute.

[[Page 11947]]

Multimedia submissions (audio, video, etc.) must be accompanied by a 
written comment. The written comment is considered the official comment 
and should include discussion of all points you wish to make. The EPA 
will generally not consider comments or comment contents located 
outside of the primary submission (i.e., on the web, cloud, or other 
file sharing system). For additional submission methods, the full EPA 
public comment policy, information about CBI or multimedia submissions, 
and general guidance on making effective comments, please visit http://www2.epa.gov/dockets/commenting-epa-dockets.

FOR FURTHER INFORMATION CONTACT: Kate Gregory, Air Program, 
Environmental Protection Agency, 1595 Wynkoop Street, Denver, Colorado 
80202-1129, (303) 312-6175, or by email at [email protected].

SUPPLEMENTARY INFORMATION: 

I. Background

    States are required to submit progress reports that evaluate 
progress towards the RPGs for each mandatory federal Class I area \1\ 
(Class I area) within the state and in each Class I area outside the 
state that may be affected by emissions from within the state. 40 CFR 
51.308(g). In addition, the provisions of 40 CFR 51.308(h) require 
states to submit, at the same time as the 40 CFR 51.308(g) progress 
report, a determination of the adequacy of the state's existing 
regional haze SIP. The first progress report must take the form of a 
SIP revision and is due 5 years after submittal of the initial regional 
haze SIP. On January 21, 2011, South Dakota submitted the State's first 
regional haze SIP in accordance with 40 CFR 51.308.\2\
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    \1\ Areas designated as mandatory Class I federal areas consist 
of national parks exceeding 6000 acres, wilderness areas and 
national memorial parks exceeding 5000 acres, and all international 
parks that were in existence on August 7, 1977 (42 U.S.C. 7472(a)). 
Listed at 40 CFR part 81, subpart D.
    \2\ 77 FR 24845 (April 26, 2012). EPA fully approved South 
Dakota's regional haze SIP submittal addressing the requirements of 
the first implementation period for regional haze.
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    On January 27, 2016, South Dakota submitted as a revision to its 
SIP a progress report which detailed the progress made in the first 
planning period toward implementation of the Long Term Strategy (LTS) 
outlined in the 2011 regional haze SIP submittal, the visibility 
improvement measured at Class I areas affected by emissions from South 
Dakota sources, and a determination of the adequacy of the State's 
existing regional haze SIP. The State provided public notice for 
comment on the Progress Report from December 22, 2015, to January 20, 
2015, and received no comment. The EPA is proposing to approve South 
Dakota's January 27, 2016 SIP submittal.

II. EPA's Evaluation of South Dakota's Progress Report and Adequacy 
Determination

A. Regional Haze Progress Report

    This section includes the EPA's analysis of South Dakota's Progress 
Report and an explanation of the basis for the Agency's proposed 
approval. The State's Progress Report evaluates the most recent 
visibility results against the 2018 Uniform Rate of Progress Goals (URP 
Goals), instead of the 2018 RPGs specified in the regional haze 
regulations. South Dakota's Progress Report explains they used the URP 
Goals because ``South Dakota's Class I areas have exceeded the 
reasonable progress goals that were established'' and ``[w]ith 
emissions reductions that are expected from the addition of BART 
controls at Big Stone and other facilities throughout the region, DENR 
expects that the improvements will continue and South Dakota's Class I 
areas will meet the 2018 uniform rate of progress goals.'' \3\ Since 
the regional haze regulations require an evaluation of visibility 
progress against the 2018 RPGs, our evaluation of South Dakota's SIP 
focuses on the RPGs.
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    \3\ South Dakota Progress Report, Appendix B, p. B-2.
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1. Control Measures
    In its Progress Report, South Dakota summarizes the emissions 
reduction measures that were relied upon by South Dakota in its 
regional haze plan for ensuring reasonable progress at the two Class I 
areas within the State: Badlands and Wind Cave National Parks. The 
State's regional haze SIP established reasonable progress goals for 
2018.\4\ The emission reduction measures include applicable federal 
programs (e.g., mobile source rules), various existing South Dakota air 
quality rules, and a plan to ``investigate the impacts of a smoke 
management plan'' to determine what level of fires and what best 
management practices should be included in the plan, with the results 
adopted into the SIP as part of the LTS.\5\ South Dakota also reviewed 
the status of Best Available Retrofit Technology (BART) requirements 
for the sole BART-subject source in the state: The Big Stone I coal-
fired power plant, owned by Montana-Dakota Utilities Company, 
NorthWestern Energy, and Otter Tail Power Company, located near Big 
Stone City, South Dakota.
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    \4\ 40 CFR 52.2170(c)(1). 77 FR 24845, 25855 (April 26, 2012) 
(final RH SIP approving South Dakota's Regional Haze SIP, Amendment, 
Section 7.2, Table 7-1, p. 106). 76 FR 76646, 76664 (December 8, 
2011) (proposed RH SIP approval, Tables 20 and 21).
    \5\ South Dakota's Regional Haze State Implementation Plan: 5-
Year Progress Report, p. 6 (``South Dakota Progress Report''). South 
Dakota SIP. pp. 121-122 (January 18, 2011 submittal).
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    The Progress Report presents the extensive information collected 
and analyzed to investigate the impacts of a smoke management plan.\6\ 
In reviewing ``the annual values for the aerosol species at the Wind 
Cave National Park'' the State ``was concerned about the extremely high 
value for particulate organic mass and elemental carbon in 2010.'' The 
report further explained that ``[d]ue to the fact that particulate 
organic mass and elemental carbons are typically associated with fire, 
the DENR researched a fire database'' and found that ``[i]n 2010, the 
National Park Service conducted a 5,500 acre prescribed fire at the 
Wind Cave National Park just a mile from the monitoring site.'' The 
Progress Report explains that this fire created two of the 20% most 
impaired days at the park and the main contributor was particulate 
organic mass.'' \7\
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    \6\ South Dakota Progress Report, pp. 9-12, 19-21, 24-27, 29-33, 
37, 40-42.
    \7\ South Dakota Progress Report, p. 11. The results of this 
fire are discussed in more detail in Sections 3.5 and 3.6 of the 
Report.
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    In analyzing changes in nitrogen oxide emissions from 2002 through 
2011, the Report explained that ``[t]he only real increase in nitrogen 
oxide emissions was from anthropogenic fires with an increase of 970 
tons per year.'' \8\ Notably, during the same timeframe, the Report 
noted that ``sulfur dioxide emissions in South Dakota decreased by just 
less than 8,500 tons per year'' and that ``[t]he largest decreases were 
seen in anthropogenic off-road mobile and point sources with a small 
decrease in natural fire.'' \9\ The State also looked at primary 
organic aerosol emissions that ``are produced by both anthropogenic and 
natural sources but are most commonly associated with fire,'' and found 
that for 2002-2011 timeframe ``[t]he largest decrease was seen in 
natural fires at just fewer than 4,000 tons.'' \10\ The Report included 
information on elemental carbon emissions, noted that natural sources 
of those emissions include fire. The State explained that while there 
was a small decrease in natural fire over the 2002-2011 timeframe, the 
data showed minor

[[Page 11948]]

increases in anthropogenic fire.\11\ During the same timeframe fine 
soil emissions decreased, which included decreases in natural fire.\12\ 
South Dakota also included information in the Report on coarse soil 
emissions over the 2002-2011 timeframe, and while there was an increase 
of over 57,000 tons during that timeframe, anthropogenic fire 
contributed to only 223 tons of those emissions.\13\ Additionally, 
while the Report shows ammonia emissions increased over the 2002-2011 
timeframe by ``just over 9,500 tons,'' emissions from natural fire 
decreased.\14\ Overall nitrogen dioxide emissions and natural biogenic 
emissions decreased, however, there were small increases from 
anthropogenic fires.\15\ The Report shows both volatile organic 
compound (VOC) emissions and carbon monoxide (CO) emissions decreasing 
over the 2002-2011 timeframe, despite increases in anthropogenic fire 
at 9,551 tons and 38,155 tons respectively.\16\
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    \8\ South Dakota Progress Report, pp. 17-18.
    \9\ South Dakota Progress Report, p. 17.
    \10\ South Dakota Progress Report, p. 19.
    \11\ South Dakota Progress Report, pp. 20-21.
    \12\ South Dakota Progress Report, p. 22.
    \13\ South Dakota Progress Report, p. 23.
    \14\ South Dakota Progress Report, p. 24.
    \15\ South Dakota Progress Report, p. 24.
    \16\ South Dakota Progress Report, pp. 25-27.
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    In its Progress Report, South Dakota provides Interagency 
Monitoring of Protected Visual Environments (IMPROVE) data which shows 
the impacts of prescribed fires conducted by the National Park Service 
(NPS) at Wind Cave National Park in 2009 and 2010.\17\ The Report 
includes two examples of the IMPROVE data that show that the NPS 
prescribed fires on both September 3, 2009, and October 20, 2010, 
contributed high levels of both particulate organic mass and elemental 
carbon on both days.\18\ Additionally, the Report provides monitoring 
data which shows that particulate organic matter is ``the second 
largest contributor [sic?] to visibility extinction at the Badlands 
National Park during the 20% most impaired days'' and that particulate 
matter (PM) is typically the product of fire.\19\ South Dakota also 
provides analysis which shows particulate mass levels on the 20 percent 
most impaired days without the impacts from the NPS prescribed fires. 
This analysis shows that ``if Wind Cave National Park would not have 
experienced the prescribed fires by Federal Land Managers, the Wind 
Cave's National Park's particulate organic mass levels would be below 
the Uniform Glide Slope similar to the Badlands National Park Uniform 
Glide Slope for particulate organic mass''.\20\ Additionally, the State 
explained that while it was preparing the Progress Report, more 
prescribed fire events occurred in 2015 that will likely show impacts 
to the Class I areas.\21\ Finally, in its Progress Report, South Dakota 
explains that ``DENR and Federal Land Managers in South Dakota have 
improved coordination and communications over the past few years and 
plan to continue that effort to help mitigate the impacts of prescribed 
fires'' at Wind Cave and Badlands National Parks.\22\
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    \17\ South Dakota Progress Report, p. 29.
    \18\ South Dakota Progress Report, Table 3-28, p. 31 and Table 
3-29, p. 33.
    \19\ South Dakota Progress Report, Table 3-10, pp. 35, 37.
    \20\ South Dakota Progress Report, p. 40 and Figures 3-22, 3-23, 
p. 41.
    \21\ South Dakota Progress Report, p. 33.
    \22\ South Dakota Progress Report, pp. 41-42, Appendix B, pp. B-
2--B-3. At the suggestion of the National Park Service, the DENR 
also looked at the Fire Emissions Tracking System and noted that it 
may be a useful tool going forward as the DENR continues to track 
prescribed fires and their impacts on the Class I areas.
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    In its Progress Report, South Dakota provides an update on the 
status of the BART determination at the Big Stone I power plant and the 
subsequent action taken given the determination. The BART 
determination, which was finalized for Big Stone I on December 7, 2010, 
was approved by the EPA,\23\ and includes a selective catalytic 
reduction (SCR) system and separated over-fire-air (SOFA) installed in 
the power plant's main boiler for nitrogen oxide (NOX) 
control, a dry flue gas desulfurization (FGD) system for sulfur dioxide 
(SO2) control, and a fabric filter system for PM 
control.\24\ In the Progress Report, the State describes the 
installation and operation of the required BART controls by the end of 
2015, as required by the State's Regional Haze Implementation Plan.\25\ 
The EPA has confirmed installation and operation of the pollution 
controls the State describes in its Progress Report, and has confirmed 
that the emissions limits in the SIP were met by the required date of 
June 28, 2017.\26\
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    \23\ 76 FR 24845 (April 26, 2012).
    \24\ 37 SDR 111 (December 7, 2010).
    \25\ 77 FR 24845 (April 26, 2012).
    \26\ Big Stone Annual Emissions 2000-2017, information available 
in the docket.
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    As shown in Table 1, BART controls at Big Stone I have resulted in 
a substantial decrease in both SO2 and NOX 
emissions (a 94 and 91 percent decrease in emissions from 2013 2014 
levels, respectively).\27\ These are larger reductions in emissions 
than the State estimated in the Progress Report and represent a clear 
downward trend since BART controls were installed and operational in 
late 2015.\28\
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    \27\ Big Stone Annual Emissions 2000-2017.
    \28\ South Dakota Progress Report, p. 7.
    \29\ Big Stone Annual Emissions 2000-2017.

  Table 1--Big Stone I Power Plant Emissions Pre and Post BART Control
                       [Actual, average tons] \29\
------------------------------------------------------------------------
                                           NOX (actual,    SO2 (actual,
              Calendar year                average tons)   average tons)
 
------------------------------------------------------------------------
2000-2004 (Baseline)....................       13,090.59       16,270.48
2013, 2014 (pre BART)...................       10,860.11       14,592.54
% Emissions Reduction (baseline vs. pre              17%             10%
 BART ).................................
2016, 2017 (post BART)..................          973.18          836.33
% Emissions Reduction (pre BART vs. post             91%             94%
 BART)..................................
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    EPA proposes to find that South Dakota has adequately addressed the 
applicable provisions under 40 CFR 51.308(g)(1) regarding the 
implementation status of control measures because the State's Report 
provides documentation of the implementation of measures within South 
Dakota, including BART at the sole BART-subject source in the State and 
the State's efforts to develop the smoke management plan.
2. Emissions Reductions
    As discussed above, South Dakota focused its assessment in its 
regional haze plan and Progress Report on emissions reductions from 
pollution control strategies that were

[[Page 11949]]

implemented at the Big Stone I power plant by the end of calendar year 
2015. The EPA has confirmed installation and operation of the pollution 
controls the State describes in their Progress Report. In its Progress 
Report, South Dakota provides a comparison of Big Stone I's actual 
SO2 and NOX emission rates to BART limits for the 
pollutants 2010-2014.\30\ Additionally, South Dakota provides statewide 
SO2, NOX and PM (fine and course) emissions data 
(among other pollutants) from Western Regional Air Partnership (WRAP) 
emissions inventories.\31\ The WRAP data shows that there were 
decreases in emissions of SO2, NOX and PM (fine 
and course) over the time period (i.e., 2002, 2008, 2011) of the three 
emissions inventories listed (Plan02d, 2008 West Jump and 2011WAQDW).
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    \30\ South Dakota Progress Report, Table 3-1, p. 8.
    \31\ South Dakota Progress Report, Table 3-2, p. 8. The WRAP's 
inventories were developed using EPA's National Emissions Inventory 
(NEI) and other sources (https://www.wrapair2.org/emissions.aspx). 
The NEI is based primarily upon data provided by state, local, and 
tribal air agencies (including South Dakota) for sources in their 
jurisdiction and supplemented by data developed by the EPA.
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    The EPA proposes to find that South Dakota has adequately addressed 
the applicable provisions of 40 CFR 51.308(g)(2) regarding emissions 
reductions achieved because the State identifies emissions reductions 
for pollutants SO2, NOX and PM (fine and course) 
and presents sufficient information and discussion regarding emissions 
trends during this period.
3. Visibility Conditions
    In its Progress Report, South Dakota provides information on 
visibility conditions for the Class I areas within its borders. The 
Progress Report addressed current visibility conditions and the 
difference between current visibility conditions and baseline 
visibility conditions, expressed in terms of 5-year averages of these 
annual values, with values for the most impaired, least impaired and/or 
clearest days. The period for calculating current visibility conditions 
is the most recent 5-year period preceding the required date of the 
progress report for which data were available as of a date 6 months 
preceding the required date of the progress report.
    South Dakota's Progress Report provides figures with visibility 
monitoring data for the two Class I areas within the State: Badlands 
and Wind Cave National Parks. South Dakota reported current visibility 
conditions for both the 2007-2011 and 2009-2013 5-year time periods and 
used the 2000-2004 baseline period for its Class I areas.\32\ Table 2, 
below, shows the visibility conditions for both the 2007-2011 and 2009-
2013 5-year time periods, the difference between these current 
visibility conditions and baseline visibility conditions, and the 2018 
RPGs.
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    \32\ For the first regional haze plans, ``baseline'' conditions 
were represented by the 2000-2004 time period. See 64 FR 35730 (July 
1, 1999).

                   Table 2--Baseline Visibility, Current Visibility, Visibility Changes, and 2018 RPGs in South Dakota's Class I Areas
                                                                       [Deciviews]
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                                                                   Difference                      Difference      Difference
          Class I area           Baseline (2000- Current (2007-   (baseline vs.   More current    (current vs.    (baseline vs.        SD 2018 RPG
                                      2004)           2011)         current)       (2009-2013)    more current)   more current)
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                                                                     20% Worst Days
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Badlands National Park.........            17.1            16.3            -0.8            15.7            -0.6            -1.4               \33\ 16.30
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                                                                      20% Best Days
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Badlands National Park.........             6.9             6.5            -0.4             5.8            -0.7            -1.1                \34\ 6.64
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                                                                     20% Worst Days
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Wind Cave National Park........            15.8            14.9            -0.9            14.1            -0.8            -1.7               \35\ 15.28
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                                                                      20% Best Days
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Wind Cave National Park........             5.1             4.4            -0.7             3.9            -0.5            -1.2                \36\ 5.02
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    As shown in Table 2, both Badlands and Wind Cave National Parks saw 
an improvement in visibility between baseline and the 2007-2011 and 
2009-2013 time periods.\37\ South Dakota also reported 20 percent worst 
day and 20 percent best day visibility data for both Badlands and Wind 
Cave National Parks from 2005-2009 and 2008-2012 for each year in terms 
of 5-year averages.\38\ This data shows an improvement in visibility at 
both class 1 areas on the 20 percent

[[Page 11950]]

best days from 2005-2009 and on the 20 percent worst days from 2008-
2012.
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    \33\ 76 FR 76646, 76664 (December 8, 2011) (``South Dakota's 
reasonable progress goals for Badlands for 2018 for the 20% worst 
days represent a 0.84 deciviews improvement over baseline. . . '' 
Table 20. 77 FR 24845, 25855 (April 26, 2012) SD SIP pp. 105-106, 
(September 19, 2011) (``DENR relied on the [WRAP's] results of the 
CMAQ modeling in determining the reasonable progress achieved by 
South Dakota surrounding states, and federal regulations in South 
Dakota's Class I areas.'') South Dakota's SIP is included in the 
docket for this action).
    \34\ 76 FR 76646, 76664 (December 8, 2011) (Table 21). 77 FR 
24845, 24855 (April 26, 2012).
    \35\ 76 FR 76646, 76664 (December 8, 2011) (South Dakota's ``. . 
. reasonable progress goals for Wind Cave for 2018 represent a 0.56 
deciviews improvement over baseline.'' Table 20. 77 FR 24845, 24855 
(April 26, 2012).
    \36\ 76 FR 76646, 76664 (December 8, 2011) (Table 21). 77 FR 
24845, 24855 (April 26, 2012).
    \37\ South Dakota Progress Report, Table 3-17 and Table 3-18, p. 
16.
    \38\ South Dakota Progress Report, Table 3-17 and Table 3-18, p. 
16.
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    The EPA proposes to find that South Dakota has adequately addressed 
the applicable provisions under 40 CFR 51.308(g)(3) regarding 
assessment of visibility conditions because the State provided baseline 
visibility conditions (2000-2004), current conditions based on the most 
recently available visibility monitoring data available at the time of 
Progress Report development, the difference between these current sets 
of visibility conditions and baseline visibility conditions, and the 
change in visibility impairment from 2009-2013.
4. Emissions Tracking
    In its Progress Report, South Dakota presents data from a statewide 
emissions inventory for 2011 (2011WAQDW) and compares this data to the 
baseline emissions inventory for 2002 (Plan02d).\39\ The pollutants 
inventoried include SO2, NOX, Primary Organic 
Aerosols (POA), elemental carbon (EC), PM2.5 (fine), 
PM10 (coarse), NH3, VOCs and carbon monoxide 
(CO). The emissions inventories include the following source 
classifications: Point; area; on-road mobile; off-road mobile; area oil 
and gas; fugitive and road dust; anthropogenic fire; natural fire; 
biogenic and wind-blown dust from both anthropogenic and natural 
sources. Table 3 presents the 2002 and 2011 statewide emission 
inventories, and includes emissions from Big Stone I.
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    \39\ WRAP Plan02d represents the State's baseline year (2002) 
emissions inventory. This emissions inventory was developed for use 
in the State's original Regional Haze SIP. See 77 FR 24845 (April 
26, 2012). The 2011WAQDW emissions inventory is considered the most 
current inventory for the purposes of this element and was derived 
from the WRAP's 2011Western Air Quality Data Warehouse project for 
South Dakota.
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    Overall, as the table shows, South Dakota's emissions that affect 
visibility were reduced in all sectors for all pollutants, except for 
POA and NH3. Compared to the 2002 emission inventory South 
Dakota used to model haze (Plan02d), emissions in 2011 (2011WAQDW) were 
reduced by 38 percent for SO2, 48 percent for 
NOX, 4 percent for PM2.5 and 9 percent for 
PM10, respectively. There were slight increases in both POA 
and NH3 as can be seen in Table 3.40 41 
Furthermore, the State provides actual SO2 and 
NOX emissions from Big Stone I, which demonstrates that 
emissions of both pollutants are trending lower per Table 1 above.\42\
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    \40\ South Dakota Progress Report, Tables 3-19, 3-20, 3-21, 3-
23, 3-24, 3-25, pp. 17-24.
    \41\ Many important changes in emissions inventory methodology 
occurred between 2007 or 2008 and the most current emissions 
inventory data presented by the State (2011WAQDW). One methodology 
change was the reclassification of some off-road mobile sources in 
the area source category, which may have resulted in the increase in 
NH3 and POA in the above comparison rather than an 
increase in actual emissions of these pollutants.
    \42\ South Dakota Progress Report, Table 3-1.

                           Table 3--Changes in South Dakota Total Emissions, Statewide
                                                 [Tons per year]
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                                                                  2002 (Plan02d)
                     Pollutant (all sources)                        and RH SIP         2011         Difference
                                                                       \43\         (2011WAQDW)
----------------------------------------------------------------------------------------------------------------
SO2.............................................................          22,076          13,618          -8,458
NOX.............................................................         146,764          75,560         -71,204
PM2.5...........................................................          82,414          79,058          -3,356
PM10............................................................         615,345         557,508         -57,837
POA.............................................................           9,168           9,563             395
NH3.............................................................         120,406         129,972           9,566
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    The EPA is proposing to find that South Dakota adequately addressed 
the provisions of 40 CFR 51.308(g)(4) regarding emissions tracking 
because the State compared the most recent updated emission inventory 
data available at the time of Progress Report development with the 
baseline emissions inventory used in the modeling for the regional haze 
plan.
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    \43\ 76 FR 76666, 76667, 76668 (December 8, 2011).
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5. Assessment of Changes Impeding Visibility Progress
    South Dakota also provided an assessment of any significant changes 
in anthropogenic emissions within or outside the State that have 
occurred, which included data collected during the years when there 
were prescribed fires that may have impeded progress towards reducing 
emissions or improving visibility.\44\ South Dakota documented that 
ammonium sulfate continues to be the biggest single contributor to 
regional haze for the Badlands National Park Class I area in the 
State.\45\
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    \44\ South Dakota Progress Report, Figures 3-14, 3-15, p. 32, 
Table 3-29, p. 33.
    \45\ South Dakota Progress Report, pp. 9-11.
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    South Dakota also determined that particulate matter contributes 
the most to visibility impairment at Wind Cave National Park.\46\ 
Additionally, the State presented data that shows that the prescribed 
fires at Wind Cave National Park conducted by the National Park 
Service, contributed to high levels of PM at the Class I area and, 
subsequently, the 20 percent most impaired days at the park in 2009 and 
2010, respectively.\47\ Even with the impacts from prescribed fires, 
the State's most current visibility assessments shows they are on track 
to meet the 2018 RPGs.
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    \46\ South Dakota Progress Report, Table 3-10 and p. 29.
    \47\ South Dakota Progress Report, Tables 3-28 and 3-29, pp. 31, 
33.
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    Assessment of South Dakota's contribution to haze in Class I areas 
outside of the State has shown that South Dakota emissions have, or may 
reasonably be expected to have, impacts on Class I areas in Minnesota, 
Montana, Wyoming and North Dakota.\48\ In its Progress Report, the 
State references the initial Regional Haze SIP and BART analysis for 
Big Stone I, which indicates Big Stone power plant is the only facility 
that impacts Class I areas outside of South Dakota.\49\ The BART 
controls installed and operational in late 2015 at Big Stone decreased 
NOX and SO2 emissions by 91 and 94 percent, 
respectively, which is a significant downward trend in these pollutants 
post BART.\50\ Based on these findings, the EPA proposes to approve the 
State's conclusion that there have been no significant changes in 
emissions of

[[Page 11951]]

visibility-impairing pollutants that have limited or impeded progress 
in reducing emissions and improving visibility in Class I areas 
impacted by the State's sources.
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    \48\ 76 FR 76651 (December 8, 2011).
    \49\ South Dakota Progress Report, Appendix B, p. B-1.
    \50\ Big Stone Annual Emissions 2000-2017.
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    The EPA proposes to find that South Dakota has adequately addressed 
the provisions of 40 CFR 51.308(g)(5) regarding an assessment of 
significant changes in anthropogenic emissions. The EPA proposes to 
agree with South Dakota's conclusion that there have been no 
significant changes in emissions of visibility-impairing pollutants 
which have limited or impeded progress in reducing emissions and 
improving visibility in Class I areas impacted by the State's sources.
6. Assessment of Current Implementation Plan Elements and Strategies
    In its Progress Report, South Dakota acknowledges the requirements 
of 40 CFR 51.308(g)(5) to discuss whether the current implementation 
plan elements and strategies are sufficient to enable the State, or 
other states with Class I areas affected by emissions from the State, 
to meet all established reasonable progress goals.\51\ As seen in Table 
2, South Dakota's visibility assessment using the most current 
information available (2009-2013) shows that it is meeting the 2018 
RPGs at both national parks, Badlands National Park 15.70 dv (current) 
versus 16.30 dv (2018 RPG) and Wind Cave National Park 14.10 dv 
(current) versus 15.28 dv (2018 RPG). The State also includes 
information regarding the 2018 URP Goals, but since those goals are not 
part of the 5-year assessment regulations, we do not include that 
information. The State concludes that no substantive revisions to the 
existing regional haze plan are necessary as the State is exceeding the 
2018 RPGs for Badlands and Wind Cave National Parks.
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    \51\ South Dakota Progress Report, p. 34.
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    For Badlands National Park, the State anticipates that the 2018 
visibility data will be lower than what was reported for the most 
recent data available because BART was fully implemented at Big Stone I 
by 2015. The reductions from Big Stone are significant and occurred 
after the most recent data included in the State's SIP. Second, the 
State explains that BART controls will be completed elsewhere 
throughout the region after 2013 and by 2018.\52\
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    \52\ South Dakota Progress Report, p. 45.
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    Based on these findings, the EPA proposes to approve the State's 
conclusion that visibility at Badlands National Park is anticipated to 
meet or exceed the RPG for 2018.
    For Wind Cave National Park, the State's visibility assessment in 
Table 2 shows that the State is currently meeting the 2018 RPG. 
Additionally, the emissions reductions from Big Stone I are significant 
and occurred after the most recent visibility data available. The State 
expects additional improvements in visibility from these reductions. 
The State's report concludes, that the current implementation plan is 
meeting the ``reasonable progress goals.'' \53\ Although the State's 
visibility assessment demonstrates that it is meeting the 2018 RPGs, 
the State explains that emission reductions from Big Stone I are 
significant and occurred after the most recent visibility data was 
available.
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    \53\ South Dakota Progress Report, p. 45.
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    The State's SIP explains that particulate organic mass level is the 
number one contributor to visibility degradation at Wind Cave National 
Park,\54\ and the level varies depending on the year and the number of 
the wildfires.\55\ The SIP explains that the despite the spikes in 
particulate organic mass at Wind Cave, decreases in ammonium sulfate, 
ammonium nitrate and other aerosol species have led to decreased 
deciview levels at the Wind Cave National Park. The DENR anticipates 
this trend will continue and improve as the DENR continues to work with 
the National Park Service on prescribed fires in the Badlands and Wind 
Cave National Parks.\56\
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    \54\ South Dakota Progress Report, p. 40.
    \55\ South Dakota Progress Report, p. 38.
    \56\ South Dakota Progress Report, pp. 41-42.
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    The EPA proposes to find that South Dakota has adequately addressed 
the provisions of 40 CFR 51.308(g) regarding the strategy assessment, 
including the State's efforts to investigate the impacts of a smoke 
management plan, and agrees with the State's determination that its 
regional haze plan is sufficient to meet the RPGs for its Class I 
areas.
7. Review of Current Monitoring Strategy
    For progress reports for the first implementation period, the 
provisions under 40 CFR 51.308(g) (7) require ``a review of the State's 
visibility monitoring strategy and any modifications to the strategy as 
necessary.'' In its Progress Report, South Dakota summarizes the 
existing monitoring network in the State to monitor visibility at 
Badlands and Wind Cave National Parks, which consists of DENR relying 
on the national IMPROVE network to meet monitoring and data collection 
goals.\57\ There are currently IMPROVE sites located in both Badlands 
and Wind Cave National Parks.\58\ Therefore, the State concludes that 
no modifications to the existing visibility monitoring strategy are 
necessary. The State will continue its reliance on the IMPROVE 
monitoring network. The IMPROVE monitoring network is the primary 
monitoring network for regional haze, both nationwide and in South 
Dakota.
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    \57\ South Dakota Progress Report, p. 42.
    \58\ South Dakota Progress Report, p. 2.
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    The State also explains the importance of the IMPROVE monitoring 
network for tracking visibility trends at the Class I areas in South 
Dakota. South Dakota states that in the future the data produced by the 
IMPROVE monitoring network will be used for preparing the regional haze 
progress reports and SIP revisions, and thus, the monitoring data from 
the IMPROVE sites needs to be readily accessible and be kept up-to-
date. The Visibility Information Exchange Web System website has been 
maintained by WRAP and the other Regional Planning Organizations to 
provide ready access to the IMPROVE data and data analysis tools.
    In addition, the State operates additional non-IMPROVE monitors in 
both Badlands and Wind Cave National Parks which help South Dakota 
characterize air pollution levels in areas across the State, and 
therefore aid in the analysis of visibility improvement in and near its 
Class I areas.\59\
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    \59\ South Dakota Progress Report, p. 42.
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    The EPA proposes to find that South Dakota has adequately addressed 
the applicable provisions of 40 CFR 51.308(g)(7) regarding monitoring 
strategy because the State reviewed its visibility monitoring strategy, 
and determined that no further modifications to the strategy are 
necessary.

B. Determination of Adequacy of the Existing Regional Haze Plan

    The provisions under 40 CFR 51.308(h) require states to determine 
the adequacy of their existing implementation plan to meet existing 
goals. South Dakota's Progress Report includes a negative declaration 
regarding the need for additional actions or emissions reductions in 
South Dakota beyond those already in place and those to be implemented 
by 2018 according to South Dakota's regional haze plan.\60\
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    \60\ South Dakota Progress Report, p. 45.
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    The EPA proposes to conclude that South Dakota has adequately 
addressed 40 CFR 51.308(h) because the visibility trends at both Class 
I areas in the State, Badlands and Wind Cave National Parks, indicate 
that the relevant RPGs

[[Page 11952]]

will be met via emission reductions already in place.

III. Proposed Action

    The EPA is proposing to approve South Dakota's January 27, 2016, 
Regional Haze Progress Report as meeting the applicable regional haze 
requirements set forth in 40 CFR 51.308(g) and 51.308(h).

IV. Statutory and Executive Order Reviews

    Under the CAA, the Administrator is required to approve a SIP 
submission that complies with the provisions of the Act and applicable 
federal regulations. See 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in 
reviewing SIP submissions, the EPA's role is to approve state choices, 
provided that they meet the criteria of the CAA. Accordingly, this 
proposed action merely proposes to approve state law as meeting federal 
requirements and does not impose additional requirements beyond those 
imposed by state law. For that reason, this proposed action:
     Is not a significant regulatory action subject to review 
by the Office of Management and Budget under Executive Orders 12866 (58 
FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21, 2011);
     Is not expected to be an Executive Order 13771 regulatory 
action because this action is not significant under Executive Order 
12866;
     Does not impose an information collection burden under the 
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
     Is certified as not having a significant economic impact 
on a substantial number of small entities under the Regulatory 
Flexibility Act (5 U.S.C. 601 et seq.);
     Does not contain any unfunded mandate or significantly or 
uniquely affect small governments, as described in the Unfunded 
Mandates Reform Act of 1995 (Pub. L. 104-4);
     Does not have federalism implications as specified in 
Executive Order 13132 (64 FR 43255, August 10, 1999);
     Is not an economically significant regulatory action based 
on health or safety risks subject to Executive Order 13045 (62 FR 
19885, April 23, 1997);
     Is not a significant regulatory action subject to 
Executive Order 13211 (66 FR 28355, May 22, 2001);
     Is not subject to requirements of Section 12(d) of the 
National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 
note) because this action does not involve technical standards; and
     Does not provide the EPA with the discretionary authority 
to address, as appropriate, disproportionate human health or 
environmental effects, using practicable and legally permissible 
methods, under Executive Order 12898 (59 FR 7629, February 16, 1994).
    The SIP is not approved to apply on any Indian reservation land or 
in any other area where the EPA or an Indian tribe has demonstrated 
that a tribe has jurisdiction. In those areas of Indian country, the 
rule does not have tribal implications as specified by Executive Order 
13175 (65 FR 67249, November 9, 2000), nor will it impose substantial 
direct costs on tribal governments or preempt tribal law.

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Incorporation by 
reference, Intergovernmental relations, Nitrogen oxides, Particulate 
matter, Reporting and recordkeeping requirements, Sulfur dioxide, 
Volatile organic compounds.

    Authority:  42 U.S.C. 7401 et seq.

    Dated: March 13, 2018.
Douglas H. Benevento,
Regional Administrator, Region 8.
[FR Doc. 2018-05398 Filed 3-16-18; 8:45 am]
 BILLING CODE 6560-50-P